Bottle bottom



FIG. 1 is a bottom perspective view showing our design with the remainder of a representative bottle being shown in phantom outline for purposes of showing the environment in which the design is used, and forming no part of the claimed design;

FIG. 2 is a side elevational view of our design, which appears the same from all directions, and with the remainder of a representative bottle being shown in phantom outline for purposes of showing the environment in which the design is used;

FIG. 3 is a top plan view of our design; and,

FIG. 4 is a bottom plan view of our design. 

The ornamental design for a bottle bottom, as shown in the accompanying drawings and described. 